Overall results in this ABC News/Washington Post poll mark the public's longstanding emphasis on security over privacy. Sixty-four percent support the use of the scanning machines, even though they produce x-ray images of a passenger's unclothed body that security officials can see. Half as many are opposed, and "strong" supporters outnumber strong opponents, also by 2-to-1.

Views are more divided, though, on the Transportation Security Administration's (TSA) new pat-down procedures, to be used on people who decline the full-body scan, or whose electronic screening indicates a need for further examination. While 48 percent see the new pat-downs as justified, 50 percent say they go too far -- including a majority, 54 percent, of people who fly at least once a year. And strength of sentiment runs negatively on this issue: Among all adults 37 percent are strongly opposed, vs. 29 percent who strongly support the pat-down rule.

HEALTH and RISK -- In addition to privacy, health impacts are a concern, or at least an open question, with a strong relationship to views on the new scanning machines. Fifty-two percent of Americans don't think the scanners raise a serious health concern -- but that leaves 48 percent who either think they may pose a health risk (35 percent) or who are unsure (13 percent).

It matters: Support for using the scanners plummets by 32 points among those who suspect a possible health risk, to 45 percent, compared with 77 percent support among those who see no such concern. That suggests the TSA might mitigate opposition if it were able to persuade more of the public that the scanners, even if intrusive, are safe.

Partisanship Does Not Play Role in Support for Scanners

Risk perception is another factor: Support for the scanners is 15 points higher among people who are worried about the risk of terrorism in air travel, and support for the new pat-down approach is a slight 9 points higher in this group.

Support for both, then, could rise if security were more of a concern; as things stand, 30 percent say they're worried about the risk of terrorism in air travel -- a new low in polling since two days after 9/11, when it peaked at nearly twice that number.

Interestingly, in these partisan times, there aren't substantial differences between Democrats and Republicans in support for the new scanning devices (69 and 65 percent, respectively), or in views on the new pat-down procedures. (Independents are somewhat less enamored of both.)

FLIERS -- The results, as noted, differ among travel groups. People who fly at least annually are 12 points more apt to oppose the new screening machines and a slight eight points more apt to criticize the new pat-downs as an unjustified intrusion on personal privacy.